Electrical Safety: Grounding, Residual Current Circuit Breakers, and Power in Wet Environments

Why Food Plants Need Extra Care

Water and electricity are a dangerous combination. Floors in food plants and central kitchens are often wet, machines are washed down with water, steamers and steam make the air humid, and stainless steel worktables and floors are good conductors. If a wire's insulation is damaged or a machine housing leaks current, a person standing on a wet floor who touches the housing can be electrocuted.

Do Machines Need to Be Grounded?

Yes. Article 239-1 of the Occupational Safety and Health Facilities Regulations (職業安全衛生設施規則; current text last amended June 30, 2026) requires employers to ground the non-current-carrying metal parts of electrical equipment in use according to the Electrical Installation Regulations for Consumers (用戶用電設備裝置規則).

The purpose of grounding is that if internal insulation fails and the housing becomes live, the current flows away through the ground wire and trips the residual current circuit breaker or overcurrent protection, instead of passing through a person. In practice:

• Use three-prong plugs with a ground pin and grounded outlets; don't use adapters that "skip" the ground pin.
• For hard-wired machines, the ground wire must be securely fastened to the housing's ground terminal.
• After moving a machine or rewiring, confirm the ground is still connected.

Article 239 also requires that electrical equipment and wires in use meet national standards.

Do You Need Residual Current Circuit Breakers?

Article 243 of the Facilities Regulations requires that, to prevent electric shock from leakage, high-sensitivity, high-speed residual current circuit breakers that operate reliably be installed on the circuits connected to electric tools in the following situations:

1. Using mobile or portable electric tools with a voltage to ground of 150 volts or more.
2. Using mobile or portable electric tools in wet locations moistened by water or other highly conductive liquids, or on metal plates, steel frames, or other highly conductive locations.
3. Temporary electrical equipment for construction or engineering work.

Article 244 lists exceptions: electric tools connected to ungrounded circuits, used on insulated platforms, or with double-insulated construction.

For permanently installed machines, whether to add residual current circuit breakers to the distribution circuit follows the Electrical Installation Regulations for Consumers for wet locations and similar cases, designed and installed by qualified electrical technicians. The Electrical Installation Regulations for Consumers list "commercial professional kitchens" and "cold storage plants" as examples of wet locations.

Using Power in Wet Environments

• Protection and insulation: Article 241 of the Facilities Regulations requires live parts of electrical equipment that could cause electric shock on contact to have guards or insulating covers; Article 246 requires measures to prevent insulation damage or aging where insulated wiring or mobile cords could be contacted.
• Keep cords off the floor and out of water: Raise mobile cords or protect them with sleeves; Article 253 states that, in principle, temporary wiring or mobile cords must not be used on passageways.
• Label switches: Article 248 requires devices for switching motors or electrical equipment on and off to be clearly labeled with their switching operation and purpose.
• Don't operate switches with wet hands: Article 276, Subparagraph 8.
• When washing down: Stop the machine and cut power before washing it down; don't spray electrical cabinets, motors, or outlets directly unless the equipment's marked waterproof rating allows it.
• Electrical installation and repair: Article 276, Subparagraph 1 states that installation, maintenance, and servicing of a plant's electrical equipment may only be carried out by qualified electrical technicians.

De-Energized Work and Lockout

Article 276, Subparagraph 2: when power is cut to adjust electrical machinery, the switch must be locked out or tagged and signed immediately after being turned off; when restoring power, the person who signed the tag must remove the lock or tag. For the full procedure, see lockout rules.

Get the Power Specifications Right First

Before connecting, confirm that the machine's voltage, phases, and power match the site's supply. Taking Dong-Yih models as examples: the Sweet Potato Ball & Taro Ball Portioning Machine DY-528MS is single-phase 220V, 1.6KW, with three-phase 380/415/440V available by special order; the Automatic Bun & Mantou Machine DY-201 is rated at 2.0KW. Don't rewire a machine yourself if its power specifications don't match.

FAQ

Q: Do machines need to be grounded?
A: Yes. Article 239-1 of the Occupational Safety and Health Facilities Regulations requires the non-current-carrying metal parts of electrical equipment to be grounded according to the Electrical Installation Regulations for Consumers.

Q: Do we need residual current circuit breakers?
A: Article 243 of the Facilities Regulations requires high-sensitivity, high-speed residual current circuit breakers when using mobile or portable electric tools in wet locations or on metal plates or steel frames, and when using mobile or portable electric tools with a voltage to ground of 150 volts or more; fixed circuits follow the Electrical Installation Regulations for Consumers.

Q: What should we watch for when using power in wet environments?
A: Ground housings properly, install residual current circuit breakers, keep cords raised and out of water, don't operate switches with wet hands, stop the machine and cut power before washing down, and have qualified electrical technicians install and repair electrical equipment.